title: Identification of the bacterial endosymbionts in leaf nodules of Pavetta (Rubiaceae).
abstract: Three genera in the Rubiaceae (Pavetta, Psychotria and Sericanthe) harbour bacterial endosymbionts within leaf nodules or galls. The present paper identifies the bacterial endophytes in three leaf-nodulating Pavetta species. In order to reveal their identity and assess their phylogenetic position, 16S rRNA, recA and gyrB genes were sequenced from an extensive sampling of Burkholderia strains. This multigene approach results in a robust phylogeny, which places the bacterial endosymbionts of Pavetta at two distinct positions within the genus Burkholderia (class Betaproteobacteria), suggesting that leaf-nodulating endosymbionts within Pavetta have different origins. The endophytes of nodulated Psychotria species were recognized as the closest relatives to the Pavetta endosymbionts. Our results suggest that the endosymbionts of Pavetta represent novel species, which can be classified as 'Candidatus Burkholderia hispidae', 'Candidatus Burkholderia rigidae' and 'Candidatus Burkholderia schumannianae'.
authors.affiliation: Laboratory of Plant Systematics, K.U. Leuven, Kasteelpark Arenberg 31, PO Box 2437, BE-3001 Leuven, Belgium.
authors.forename: Benny
authors.initials: B
authors.lastname: Lemaire
authors.affiliation: Laboratory of Plant Growth and Development, University of Antwerp, Department of Biology, Groenenborgerlaan 171, BE-2020 Antwerp, Belgium.
authors.forename: Sandra
authors.initials: S
authors.lastname: Van Oevelen
authors.affiliation: National Botanic Garden of Belgium, Domein van Bouchout, BE-1860 Meise, Belgium.
authors.forename: Petra
authors.initials: P
authors.lastname: De Block
authors.affiliation: Laboratory of Plant Systematics, K.U. Leuven, Kasteelpark Arenberg 31, PO Box 2437, BE-3001 Leuven, Belgium.
authors.forename: Brecht
authors.initials: B
authors.lastname: Verstraete
authors.affiliation: National Herbarium of The Netherlands, Leiden University, PO Box 9514, 2300 RA Leiden, The Netherlands.|Netherlands Centre for Biodiversity Naturalis, PO Box 9517, 2300 RA Leiden, The Netherlands.|Laboratory of Plant Systematics, K.U. Leuven, Kasteelpark Arenberg 31, PO Box 2437, BE-3001 Leuven, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Smets
authors.affiliation: Laboratory of Plant Growth and Development, University of Antwerp, Department of Biology, Groenenborgerlaan 171, BE-2020 Antwerp, Belgium.
authors.forename: Els
authors.initials: E
authors.lastname: Prinsen
authors.affiliation: National Botanic Garden of Belgium, Domein van Bouchout, BE-1860 Meise, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Dessein
mesh_terms: D019117:Burkholderia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D016000:Cluster Analysis; D027081:DNA Gyrase / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000382:microbiology* / Q000502:physiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics; D019666:Rubiaceae / Q000382:microbiology* / Q000502:physiology*; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D011938:Rec A Recombinases; D027081:DNA Gyrase